Concave ring for cone crushers

ABSTRACT

A crusher is disclosed of the type having a crushing chamber defined between a vertical conical head and a surrounding replaceable concave ring. The inside of the concave ring is provided with a stepped surface comprising alternately, annular crushing surfaces and annular connecting surfaces. The inside of the concave ring is also provided with vertical corrugations defined by alternate grooves and ridges which begin at the top and material inlet end of the concave ring, and extend downwardly to one of the annular crushing surfaces at a horizontal level above at least the lowermost annular crushing surface. The ridges of the corrugations provide a proper nip angle for crushing at the top of the chamber while the grooves provide a larger area feed opening than could be provided by a noncorrugated surface making a proper nip angle for crushing. The bottom crushing surface, which is below the corrugations, provides a smooth annular surface for fine crushing. When wear of this bottom crushing surface requires the cone to be raised, to restore predetermined spacing, the size of the feed opening at top is not reduced because wear is deliberately accelerated at the top of the chamber by providing the corrugations which cause the feed material to be nipped only by the ridges of the corrugations which are thereby worn away at a relatively rapid rate. Thus, the wearing away of the ridges of the corrugations means that when the cone is raised to compensate for wear at the bottom of the chamber the feed opening is not thereby made smaller than when the ring was new.

ited States Patent [72] inventors Edgar S. Burlrhardt [54] CONCAVE RINGFOR CONE CRUSHERS 10 Claims, 3 Drawing Figs.

52 U.S.Cl 241/214,

- 214/299 51 int. Cl B02c 2/04 501 Field ofSearch 241/207,

[56] References Cited UNITED STATES PATENTS 20,941 7/1858 Erkson 241/214X 1,894,601 H1933 Symons 241/215 Primary Examiner-Othell M. SimpsonAttameys- Arthur M. Streich, Robert B. Benson and John P.

Hines ABSTRACT: A crusher is disclosed of the type having a crushingchamber defined between a vertical conical head and a surroundingreplaceable concave ring. The inside of the concave ring is providedwith a stepped surface comprising alternately, annular crushing surfacesand annular connecting surfaces The inside of the concave ring is alsoprovided with vertical corrugations defined by alternate grooves andridges which begin at the top and material inlet end of the concavering, and extend downwardly to one of the annular crushing surfaces at ahorizontal level above at least the lowermost annular crushing surface.The ridges of the corrugations provide a proper nip angle for crushingat the top of the chamber while the grooves provide a larger area feedopening than could be provided by a noncorrugated surface making aproper nip angle for crushing. The bottom crushing surface, which isbelow the corrugations, provides a smooth annular surface for finecrushing. When wear of this bottom crushing surface requires the cone tobe raised, to restore predetermined spacing, the size of the feedopening at top is not reduced because wear is deliberately acceleratedat the top of the chamber by providing the corrugations which cause thefeed material to be nipped only by the ridges of the corrugations whichare thereby worn away at a relatively rapid rate. Thus, the wearing awayof the ridges of the corrugations means that when the cone is raised tocompensate for wear at the bottom of the chamber the feed opening is notthereby made smaller than when the ring was new.

PATENTEnncr 19 |97| @5223 MUM CONCAVE RING FOR CONE CRUSHERS BACKGROUNDOF THE INVENTION 1. Field of the Invention This invention relates torock-crushing machines having a conical head and a surrounding shellthat defines therebetween and an.-annular crushing chamber, and inparticular to such a machine having a replaceable concave ring linersupported by the shell, in which the concave ring is providedwith aspecial internal configuration which defines an outer wall of thecrushing chamber around the conical head.

2. Description of the Prior Art Crushers known to the prior art of thetype referred to are of perhaps three types. One type discloses aconcave ring having intemal'corrugations in vertical planes, a secondtype-dis-' closes a concave ring having internal horizontal annularsteps, and a third type discloses combinations of the first and secondtype.

Typical examples of the first type, disclosing corrugations on the'innersurface of a chamber-defining ring,-with.crests and valleys eachdisposed in a vertical plane, include: U.S.- Pat. No. 112,560 of 1871;,U.S. Pat. No.41 1,881 of 1889; U.S. Pat. No."759,643 'of 1904; U.S. Pat.No. 845,067 and 859,835 of 1907; U.S. Pat. No. 1,083,283 of 1914; U.S.Pat. No. 1,706,944 of 1929; and U.S. Pat. No. 2,934,277 of 1960.

Typical examples of the secondtype, disclosing horizontal annular stepson the inner surface of a chamber-defining ring, include: U.S. Pat. No.669,060 of 1901: U.S. Pat. No. 1,366,985 of 1921; U.S.,Pat.No.'1,574,142 of 19.26 and US. Pat. No. 1,775,750 of 1930.

- Typical examples of the type combining corrugationsand steps includeU.S. Pat. No. 27,246 of .1860; BritishPat. No. 15,954 of 1885; andBritishPat. No- 16,837 of 1897.

A more recent example of a prior art patent disclosing concepts of theforegoing sort is U.S. Pat. No. 3,312,404 of 1967 which discloses spiralgrooves which are neither horizontal steps or vertical corrugations butnevertheless have some characteristics of both. 1t will appear fromthedescription ofthe present invention to follow, that the presentinvention distinguishes from all such prior art both in its objectives,and in the design and construction of the apparatus to achieve theobjectives.

ln order to understand the following description of the presentinvention, it is believed important to understand the teachings of theaforesaid U.S. Pat. No. 1,574,142 of 1926 to W. S. Weston and 1,775,750of 1930 to D. Cole. The Cole patent explains that a proper nip angle ina crushing chamber between a cone and concave, for passing materialthrough the crushing chamber, is one which does not exceed a maximum(defined by Weston as being 24 and now known to be as much as 28). A nipangle greater than this maximum causes material to back up rather thanpass through.

Cole also explains earlier patents to E. B. Symons and the zone ofparallelism between lower portions of the cone and concave ring whereopposing surfaces, that provide fine crushing, are approximatelyparallel at their position of maximum approach. This zone must be longenough that all particles are caught at least once by the cone andconcave ring at the instant of their closest approach. The need for thisbottom zone to be of a certain fixed length plus the fact that the angleof the chamber above this zone cannot exceed the maximum nip (about 24or slightly larger), and the fact that projecting the concave ringupwardly above the conical crushing head in order to enlarge the feedopening would not provide addi tional crushing (i.e. no crushing takesplace above the cone), are factors that collectively limit the range ofparticle size reduction that can be attained in a single crusher.

Thus Cole explains that prior to his invention, it was necessary inorder to obtain efficient cone crushing of rock to small particle sizes,to do it with two crushers. That is, a coarse crusher could be providedwith a feed opening large enough to accept the biggest particles and thedischarge therefrom could be the feed to a second crusher having thezone of parallelism long enough and close enough for fine crushing, butwith a correspondingly limited feed opening. The invention of the Colepatent provided designers a second choice, that is the same sizereduction could be achieved in one crusher as formerly required two, byproviding a stepped chamber which could open wide enough to accept thelargest pieces but without any portion of the chamber exceeding themaximum nip angle of 24 to 28.

A problem associated with Cole s solution to the previouslylong-standing problem, arises from the fact that the large pieces makeup a very small percentage of total feed. Most feed therefore passesthrough Coles chamber without touchingthe upper stepped surfaces whichtherefore wear away very slowly compared to the wear of the surfacesdefining the zone of parallelism where the fine crushing isaccomplished. It therefore becomes necessary to raise the cone and closethe gap to restore the original spacing'in the zone of parallelismbefore any appreciable wear has-taken place to the feed opening at thetop of the chamber. Raising the cone under these circumstances has theunwanted efiect of bringing theunwomtop of the cone closer to the unwomtop of the chamber and thereby making the feed opening smaller. It thenbecomes necessary to replace concave rings because not enough wear hastaken place at the top to maintain the desired feed opening. I 7

One of the objects of the present invention, as will be explained, isdirected to solving the foregoing problem.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a new and improved cone crusher and a concave ring therefore,with provisions to deliberately accelerate wear at the top thereof tothe bottom of the concave ring.

It is another objectof the present invention to provide a new andimproved conelcrusher having a concave ring with a material inletopening that will admit pieces larger than pieces of a size that canbecrushed in the nip at the inlet opening.

According to a preferred embodiment of the present invention a crusheris provided with a crushing chamber defined between a vertical conicalhead and a surrounding replaceable concave ring the inside of which isprovided with a stepped surface comprising alternately, annular-crushingsurfaces and annular connecting surfaces. The inside of theconcave ringis also provided with vertical corrugations defined by alternate groovesand ridges which begin at the top and material inlet end of the concavering, and extend downwardly to one of the annular crushing surfaces at ahorizontal level above at least the lowermost annular crushing surfaces.The ridges of the corrugations provide a proper nip angle for crushingat the top" of the chamber while the grooves provide a larger area feedopening than could be provided by a noncorrugatedsurface making a propernip angle for crushing. This larger feed area will also admit to thechamber pieces of a size larger than the size that can be nipped at theentrance to the crushing chamber. The bottom crushing surface, which isbelow the corrugations provides a smooth annular surface for finecrushing. When wear of this bottom crushing surface requires the cone tobe raised, to restore predetermined spacing, the size of the feedopening at top is not reduced because wear is deliberately acceleratedat the top of the chamber by providing the corrugations which cause thefeed material to be nipped only by the ridges of the corrugations whichare thereby worn away at a relatively rapid rate. Thus, the wearing awayof the ridges of the corrugations means that when the cone is raised tocompensate for wear at the bottom of the chamber the feed opening is notthereby made smaller than when the ring was new.

Other features and objects of the invention that have been attained willappear from the more detailed description to follow with reference to anembodiment of the present invention shown in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 of the accompanying drawingshows diagrammatically a side elevation, partly in section, a crusheraccording to the present invention;

FIG. 2 is an enlarged view of a fragment of FIG. 1; and

FIG. 3 is an enlarged fragmentary view taken along line III-Ill in FIG.2 and viewing the structure in the direction indicated by arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, an upperportion of a gyratory crusher is shown comprising a shaft 1 whichcarries a conical head 2 with a conical mantle 3 mounted thereon anddefining a space 4 between mantle 3 and head 2 which may be filled withzinc or resin. The head 2 and mantle 3 are surrounded by an annularshell within which is hung a replaceable conical and concave ring 11which is supported in a fixed position by bolts 12 that projectdownwardly through a shell flange 13 and an aligned ring flange 14. Theconcave ring 11 cooperates with conical mantle 3 on head 2, to define amaterial feed opening 15 at the top and apex end of the conical concavering 11, a material-discharging opening 16 at the bottom and base end ofthe conical concave ring 11, and a material-crushing chamber 17therebetween. Crushing action is provided by an eccentric l8 rotated (bymeans not shown) which gyrates the shaft, about a central axis A-Bpassing through ring 11, as indicated by the broken line A-C. The gapbetween the mantle 3 and ring 11 may be adjusted by raising or loweringshaft 1. Shaft 1 may be raised and lowered by a piston 19 as disclosedin U.S. Pat. No. 2,448,936.

The inner surface of concave ring 11 is provided with a stepped andcorrugated configuration that will be described with reference to FIGS.2 and 3. The stepped configuration on the inside of ring 11 comprises,alternately, an annular crushing surface 20 and an annular connectingsurface 21 between each adjacent pair of crushing surfaces 20. Theannular crushing surfaces 20 each slope outwardly away from the centralaxis A-B in a direction from the apex (top and inlet) end 15 toward thebase (bottom and outlet) end 16. The annular connecting surfaces 21 eachslope inwardly toward the central axis A-B in a direction from theapex-inlet end 15 toward the base-outlet end 16.

The corrugated configuration is superimposed upon the steppedconfiguration and the corrugations are formed by curved surfacesdefining alternate ridges 25 and grooves 26. As shown in FIG. 3 theconvex curvature of ridges 25 and concave curvature of grooves 26 eachinitially represent half of the radial distance between the crest of aridge and the bottom of groove but operation such as will be describedresults in the ridges wearing away as indicated by a broken line 25a.The ridges 25 and grooves 26 as shown in FIG. 2 begin at the apexinletend 15 of chamber 17 and extend downwardly, each in a plane parallel tocentral axis A-B, to one of the crushing surfaces 20 inwardly andupwardly of the crushing surface 20" adjacent the base-outlet end 16.Preferably, the crushing surface 20, into which the ridges 25 andgrooves 26 merge is a crushing surface closer to the apex-inlet end 15than to the basecutlet end. Crushing surface 20" presents a considerablygreater surface area to face the conical mantle 3, as it is here wherethe fine crushing occurs.

In the operation of a crusher according to the present invention havinga concave ring according to the present invention, rock of various andirregular sizes may be fed into the material feed inlet 15. As shown inFIG. 3, the feed inlet 15 will admit a piece of rock of a sizerepresented by the circle 30, which is larger than a piece of rock of asize represented by the circle 31, which can be nipped at the entrance15 to the crushing chamber 17. The advantage of this feature of thepresent invention can be considered from two viewpoints. From oneviewpoint, as shown in FIG. 3, by providing the grooves 26 the presentinvention permits pieces 30, which are larger than nipsize pieces 31, tobe admitted to the crushing chamber. From a second viewpoint, as shownin FIG. 3, by providing ridges 25 the present invention permits pieces31, which are smaller than admission-size pieces 30 to be broken at thevery entrance to the crushing chamber. From either viewpoint, it can beseen from FIG. 3, that contact provided by the present invention betweenrock and the inner surface of ring 11 is concentrated at the crests ofthe ridges 25, which as shown in FIG. 2 are also stepped to maintaingood nip angles to the top of ring 3, thus tending to promote crushingand accelerate wear of the surfaces of ridges 25 back to a surfacerepresented by broken line 25a, and thereby tending to enlarge theopening 15. Therefore, when wear of the lowermost annular crushingsurface 20 occurs, particles larger than desired sizes will begin topass through discharge opening 16. Piston 19 must then be operated (inthe manner disclosed in U.S. Pat. No. 2,448,936) to raise shaft 1 andreduce the gap between surface 20" and mantle 3. Raising mantle 3 torestore the original predetermined gap with surface 20" tends to movethe top of the cone (mantle 3) closer to the top of the conical chamberand close inlet opening 15. But this tendency has been countered by thepresent invention which provides for the acceleration of wear, byconcentrating wear on but a portion of the total surface area of ridges25 and grooves 26, and that portion is the crests of ridges 25 whichrelatively rapidly wear back to line 25a.

From the foregoing detailed description of the present invention, it hasbeen shown how the objects of the invention have been attained in apreferred manner. However, modifications and equivalents of thedisclosed concepts such as readily occur to those skilled in the art areintended to be included within the scope of this invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In a crusher having a vertical conical crushing head surrounded by anannular shell:

A. a concave ring mounted in a fixed position within the shell andsurrounding the conical head to define therebetween a top material feedopening, a materialcrushing chamber below the feed opening with apredetermined minimum spacing between the head and surrounding concavering and a bottom discharge opening;

B. an inner surface of the ring within the material-crushing chamberhaving a stepped configuration defining a plurality of annular crushingsurfaces sloped downwardly and outwardly of the head alternately withconnecting surfaces sloped downwardly and inwardly toward the head;

C. the inner surface of the ring also defining corrugations of alternateridges and grooves with the entire length of each being disposed in avertical plane; and

D. The grooves and ridges of the corrugations extend downwardly from thetop of the ring to and terminate at one of the annular crushing surfacesat a horizontal level above at least the lowermost one of the annularcrushing surfaces.

2. In a crusher according to claim 1, means for raising and lowering theconical head within and relative to the surrounding concave ring andoperable to raise the conical head after use has resulted in a wearingaway of the lowermost of the annular crushing surfaces and the ridges ofthe corrugations, to thereby restore the predetermined minimum spacingbetween the conical head and the lowermost crushing surface of theconcave ring and maintain the desired feed opening at the top of theconcave ring.

3. A crusher according to claim 1 in which the lowermost annularcrushing surface of the concave ring presents a greater surface areathan the next higher of such plurality of crushing surfaces.

4. A crusher according to claim 1 in which the feed opening at the topof the ring defines an opening of smaller outer diameter than the outerdiameter of the crushing chamber defined by the bottom of the ring, andthe ridges and grooves of the corrugations extend downwardly andradially outward of the conical head to merge into one of the annularcrushing surfaces closer to the feed opening than to the dischargeopenmg.

5. A crusher according to claim 1 in which the ridges of thecorrugations are curved surfaces.

6. A crusher according to claim 5 in which the curved surface definingeach ridge of the corrugations is a convex surface which in a horizontalplane extends radially outward at least approximately one-half of thedistance to the radially outermost portions of the adjacent grooves.

7. A concave ring having an inner surface defining a conical concavechamber about a central axis passing therethrough and having an apex endthereof of smaller diameter than a base end thereof remote of the apexend, for defining in a cone-type crusher an outer wall of a crushingchamber, and the inner surface of the concave ring having aconfiguration defining:

A. a plurality of annular steplike surfaces comprising alternately anannular crushing surface each sloped outwardly of the central axis in adirection from the apex end toward the base end and an annularconnecting surface between crushing surfaces, the connecting surfaceseach sloped inwardly toward the central axis in a direction from theapex end toward the base end;

B. a plurality of corrugations of alternately adjacent ridges andgrooves with the entire length of each being disposed in a planeparallel to the central axis; and

C. the grooves and ridges begin at the apex end of the conical concavechamber and extend therefrom to and terminate at one of the annularcrushing surfaces spaced inwardly of the crushing surface adjacent thebase end of the conical concave chamber.

8. A ring according to claim 7 in which at least the annular crushingsurface adjacent the base end of the conical concave chamber presents agreater surface area than the next inwardly adjacent of such pluralityof crushing surfaces.

9. A ring according to claim 7 in which the ridges of the corrugationsare curved surfaces.

10. A ring according to claim 9 in which the curved surface definingeach ridge of the corrugations is a convex surface which in a planeperpendicular to the central axis extends radially outward of thecentral axis at least approximately onehalf of the distance to theradially outermost portions of adjacent grooves.

1. In a crusher having a vertical conical crushing head surrounded by anannular shell: A. a concave ring mounted in a fixed position within theshell and surrounding the conical head to define therebetween a topmaterial feed opening, a material-crushing chamber below the feedopening with a predetermined minimum spacing between the head andsurrounding concave ring and a bottom discharge opening; B. an innersurface of the ring within the material-crushing chamber having astepped configuration defining a plurality of annular crushing surfacessloped downwardly and outwardly of the head alternately with connectingsurfaces sloped downwardly and inwardly toward the head; C. the innersurface of the ring also defining corrugations of alternate ridges andgrooves with the entire length of each being disposed in a verticalplane; and D. The grooves and ridges of the corrugations extenddownwardly from the top of the ring to and terminate at one of theannular crushing surfaces at a horizontal level above at least thelowermost one of the annular crushing surfaces.
 2. In a crusheraccording to claim 1, means for raising and lowering the conical headwithin and relative to the surrounding concave ring and operable toraise the conical head after use has resulted in a wearing away of thelowermost of the annular crushing surfaces and the ridges of thecorrugations, to thereby restore the predetermined minimum spacingbetween the conical head and the lowermost crushing surface of theconcave ring and maintain the desired feed opening at the top of theconcave ring.
 3. A crusher according to claim 1 in which the lowermostannular crushing surface of the concave ring presents a greater surfacearea than the next higher of such plurality of crushing surfaces.
 4. Acrusher according to claim 1 in which the feed opening at the top of thering defines an opening of smaller outer diameter than the outerdiameter of the crushing chamber defined by the bottom of the ring, andthe ridges and grooves of the corrugations extend downwardly andradially outward of the conical head to merge into one of the annularcrushing surfaces closer to the feed opening than to the dischargeopening.
 5. A crusher according to claim 1 in which the ridges of thecorrugations are curved surfaces.
 6. A crusher according to claim 5 inwhich the curved surface defining each ridge of the corrugations is aconvex surface which in a horizontal plane extends radially outward atleast approximately one-half of the distance to the radially outermostportions of the adjacent grooves.
 7. A concave ring having an innersurface defining a conical concave chamber about a central axis passingtherethrough and having an apex end thereof of smaller diameter than abase end thereof remote of the apex end, for defining in a cone-typecrusher an outer wall of a crushing chamber, and the inner surface ofthe concave ring having a configuration defining: A. a plurality ofannular steplike surfaces comprising alternately an annular crushingsurface each sloped outwardly of the central axis in a direction fromthe apex end toward the base end and an annular connecting surfacebeTween crushing surfaces, the connecting surfaces each sloped inwardlytoward the central axis in a direction from the apex end toward the baseend; B. a plurality of corrugations of alternately adjacent ridges andgrooves with the entire length of each being disposed in a planeparallel to the central axis; and C. the grooves and ridges begin at theapex end of the conical concave chamber and extend therefrom to andterminate at one of the annular crushing surfaces spaced inwardly of thecrushing surface adjacent the base end of the conical concave chamber.8. A ring according to claim 7 in which at least the annular crushingsurface adjacent the base end of the conical concave chamber presents agreater surface area than the next inwardly adjacent of such pluralityof crushing surfaces.
 9. A ring according to claim 7 in which the ridgesof the corrugations are curved surfaces.
 10. A ring according to claim 9in which the curved surface defining each ridge of the corrugations is aconvex surface which in a plane perpendicular to the central axisextends radially outward of the central axis at least approximatelyone-half of the distance to the radially outermost portions of adjacentgrooves.